1. Field of the Invention
The present invention relates to a transmission terminal that communicates predetermined data including image data with another transmission terminal connected to a communication network.
2. Description of the Related Art
Recently, transmission systems have been widely used, with which a conference or the like can be conducted through a communication network, such as the Internet. In such a transmission system, a transmission terminal including, for example, a camera, a microphone, and a speaker may be used. When the communication terminal starts a telephone call (communication) with another communication terminal, image data or audio data obtained by the camera or the microphone of the corresponding communication terminal is communicated. In this manner, with the communication terminal, a video conference can be conducted.
When a video conference is conducted by using a transmission terminal, a party of the video conference may use its own external input device, such as a personal computer (PC), besides the transmission terminal. The party of the video conference may display conference material on a display of the external input device, and may have a discussion with the other party of the video conference. The communication terminal receives display data, such as conference material, displayed by the external input device, and the communication terminal transmits the display data to the other communication terminal, which is used by the other party of the video conference.
In the communication system, an information providing device carried by the party of the video conference can be used as the external input device (cf. Patent Document 1 (Japanese Unexamined Patent Publication No. 2012-085269), for example). Patent Document 1 discloses a video conference system that displays image data of material or the like. In the video conference system, for example, a smart phone is used as the information providing device, and the information providing device communicates with the transmission terminal using Near Field Communication (NFC) or Bluetooth (registered trademark), and thereby the image data of the material is displayed.
In some cases, the party of the video conference may wish to save a screen displayed on the display of the transmission terminal. For such a need, a button for capturing the screen may be provided in the communication terminal, and the party may operate the button, depending on necessity.
On the display of the communication terminal, not only the image of the party itself which is captured by the camera, but also the image of the other party captured by the other communication terminal is displayed. Thus, if it were possible for the party to freely save the displayed image, a capture of the image of the other party could be freely produced. When the information providing device transmits display data, such as image data of conference materials, to the communication terminal, the display of the communication terminal may display an image, such image of the conference material. Accordingly, if it were possible for the party to freely capture the displayed image, a copy of important materials could be freely made.
There is a need for a transmission terminal that can restrict capturing of a displayed image, which is displayed on a display of the transmission terminal.